A. Field of the Invention
This invention relates generally to value printing systems having a modular form and, particularly, to a system wherein the secure metering device module, which contains the accounting registers for recording the values of printed indicia, also contains a representation of the indicia stored in electronic form. For example, in a modular postage printing system, wherein the secure metering module is separable from the printing module, an even greater degree of security is attained by storing within the metering module a representation of the indicia to be printed. Thus, not only must the metering module provide the printing module with permission to print the indicia, the metering module must also provide a representation of the indicia itself.
B. Prior Art
A postage meter typically includes a printer to print postal information on a mail piece. Postage meters of this type are described in a U.S. patent issued to Alton B. Eckert, Jr., Howel A. Jones, Hr. and Frank T. Check, Jr., entitled "A Remote Postage Meter Charging System Using an Advanced Micro-Computerized Postage Meter" issued on June 27, 1978, U.S. Pat. No. 4,097,923. Another example of a meter that utilizes a printer is described in U.S. Pat. No. 4,422,148 issued to John H. Soderberg and Alton B. Eckert, Jr. and Robert B. McFiggans entiled "Electronic Postage Meter Having Plural Computing Systems" issued on Dec. 20, 1983.
Postal meters of above-described form may be provided with several modifications. For example, in one modification, a remote charging feature is available whereby a key is provided for operation of a three position charging switch on the keyboard. The operator of the unit may thus be provided with suitable combinations for entry into the keyboard to enable remote charging. In a further modification the three position charging switch on the keyboard may be controlled by a simple knob without the necessity of the key. In this type of system, the meter may be manually recharged at the post office, but the service function may be affected locally in a manner similar to that of the remote charging system type units.
The postage meters above described all contain printers that are an integral part of the meter itself. Although these meters as above described serve their intended purpose in an exemplary fashion it is always important to develop new and improved postage metering devices to decrease cost and improve speed and efficiency.
As is well known, in a typical system the postage meter will contain the printing apparatus to facilitate applying postage to a mail piece of the like. The printing apparatus located within the postage meter adds to the cost and the complexity of the meter.
One such postal metering device which does not contain an integral printer is disclosed in a copending application No. 832,904, filed Feb. 25, 1986 entitled "System For Detecting Unaccounted For Printing In A Value Printing System", to G. Edelman et al, now U.S. Pat. No. 4,703,333, wherein a metering device provides a validation signal to a host having an attached printer. Thereafter the printer prints information which includes information from the validation signal.
Typically, in an electronic postal mailing system it is important that the postal funds within the meter are secure. What is meant by the funds being secure is that when the printer prints postage indicia on a mail piece, the accounting register within the postage meter always should reflect that the printing has occurred. In typical postal mailing systems, since the meter and the printer are integral units, both are interlocked in such a manner as to insure that the printing of a postage indicia cannot occur without accounting. Postal authorities generally require the accounting information to be stored within the postage meter and to be held there in a secure manner, thus any improved postal mailing system should include security features to prevent unauthorized and unaccounted for changes in the amounts of postal funds held in the meter. Postal authorities also require that meters be put in service and removed from service in strict compliance with their requirements for registration and periodic (say, for example, every 6 months) inspection. This enables the Post Office to keep records on the usage of a meter and detect fraud. Thus, there are also administrative costs associated with the record keeping, inspection and servicing of meters.
There is a continuing need for less expensive and higher speed postage meters. As before-mentioned, typically a postage meter has associated with it different peripherals that add to the cost thereof. It is important to develop postage meters that can be adaptable to postal mailing systems which are less expensive and more efficient, but will also be able to maintain the high level of security associated with the above-mentioned postage meters. It is also important that any new postal mailing system developed be one in which security can be maintained in a manner in keeping with the previously mentioned mailing systems.